Fallopia japonica
Family: Polygonaceae
Japanese knotweed
Fallopia japonica image
Emmet J. Judziewicz  
Etymology: Fallopia: for Gabriello (Gabriele) Fallopia, 16th century Italian anatomist who discovered fallopian tubes
Plants: erect to arching, perennial, 4'-10' tall, stout, shrub-like forb; speading by the long rhizomes to form clones up to several acres; stems hollow, bamboo-like, round in cross section
Leaves: alternate, up to 6" long; broadly oval with pointed tip and a straight base
Flowers: white to greenish, 5-parted, petals and petal-like sepals; inflorescence of many 3"-6" branched clusters from the upper leaf axils
Fruits: dry, 3-angled seed
Habitat: shores, grasslands, woods
Invasiveness: Restricted Invasive - Eradicate!
Conservation Status: Introduced - persisting and spreading; ecologically invasive